Well site throttling method and well site throttling system

Abstract

The application provides a throttling method at a well site, which includes: transporting natural gas from a natural gas wellhead to a ground throttling device; performing multi-stage pressure reduction and throttling on the natural gas through the ground throttling device, so as to obtain pressure of natural gas, and control the temperature of the natural gas to always be above the critical temperature of natural gas hydrate, wherein the ground throttling device includes a throttling device body, and the throttling device body includes a plurality of throttling orifice plates, so The throttle orifices are arranged at predetermined intervals; the natural gas that meets the pressure of the wellhead pipeline is transported to the downstream pipeline through the low-pressure external pipeline. This application realizes that the high-pressure natural gas at the natural gas wellhead reaches the low-pressure external transportation pipeline without generating natural gas hydrate after passing through the ground throttling device. The operation is simple, the cost is low, and the gathering and transportation process of the natural gas well site is simplified. process.

Description

technical field [0001] The present application relates to the technical field of natural gas throttling gathering and transportation, in particular to a well site throttling method and a well site throttling system. Background technique [0002] Natural gas hydrate is a crystalline compound formed by water and hydrocarbon gases in natural gas under certain pressure and temperature (higher than the freezing point of water). There is a maximum temperature for the formation of natural gas hydrate, that is, the critical temperature. If this temperature is exceeded, hydrates will not be formed no matter how high the pressure is. The formation of hydrates will block the wellbore or gas production pipeline, affecting the normal production of gas wells. [0003] In the process of gas field production, according to the characteristics of the surface development model, the depressurization production method is often adopted. Hydrates may be formed during wellbore and surface throttl...

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Problems solved by technology

[0005] The downhole choke process is to place the downhole choke at an appropriate position in the production string to achieve throttling and pressure reduction in the wellbore, transfer the surface throttling process to the wellbore, and make full use of geothermal heating to make the air flow The temperature is higher than the maximum temperature of hydrate formation under the pressure condition after throttling, and at the same time, the ground gas-gathering pipeline is buried under the permafrost, so that hydrates will not be blocked in the wellbore, wellhead and surface pipelines. The problems in this process Yes: the choke is below the formation, the operation and salvage costs are high, and underground data collection is inconvenient, making it difficult to truly understand underground gas production parameters

[0006] The antifreeze injection method refers to the injection of methanol antifreeze during the production and operation of some gas wells and gas-gathering pipelines to reduce the temperature point of hydrate formation and achieve the purpose of preventing hydrate formation. The problem with this process is: the methanol antifreeze itself High cost, increase alcohol injection equipment and operation pipeline

[0007] The ground heating throttling process, adding a heating furnace on the ground, first heating the medium to a certain temperature, and then using a throttle valve to throttle, the temperature drop caused by throttling is compensated by heating. The problem with this process is that the operating cost of the heating furnace is relatively high. High, and the furnace needs constant maintenance

[0008] Therefore, there is a need for a throttling process to solve the problem of difficult operation and high cost of the downhole throttle. It can also replace the ground throttling heating furnace and throttle valve, and can also replace the alcohol injection device to simplify the natural gas production well site gathering and transportation process.

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